Absorption ability and mechanism of fish scales from grass carp to Congo red

In this study,the sorbent was prepared from fish scale of grass carp and the absorption capability of this sorbent to different chemical dyes was determined.At the same time,the best absorption conditions and the absorption mechanism of this sorbent were studied by use of kinetic and thermodynamic analysis and FTIR assay.The results show that the adsorbent from fish scales has good absorption capacity for the dyes which have sulfonic acid group and the order of adsorbent capabilities to different dyes is:Congo red＞carmine＞brilliant blue＞sunset yellow＞methylene blue.While the temperature was 25 ℃,the absorbent dosages was 0.2 g/L,the potential of hydrogen was 7,the concentration of Congo red was 14 μg/mL,and the effect of fish scales sorbent on Congo red was the best.The quasi secondary dynamic model could reflect the isothermal absorption dynamics of different dosage of fish scales sorbent.The results of kinetic and thermodynamic analysis showed that the endothermic process of this adsorbent was spontaneous and irreversible.The infrared analysis showed that the functional groups of fish scales on Congo red absorption were composed of amino,carboxyl,phosphate groups and so on,which belonged to protein and hydroxyapatite of fish scales.